The above results obtained in Il12p40-/- and Ifng-/- mice, together with the fact that Myd88-/- mice have lower levels of Th1 cells and are highly susceptible to infection with T. cruzi (Campos et al., 2004; Oliveira et al., 2010), prompted us to address the role of MyD88-dependent pathways in the generation of CD4CTLs. The gene discussed is IFNG; the disease is infection.